Oracle Data Masking changing the data types of character columns

Customer is  using OEM 11.1.0.1.0 (11g release 1) with  Peoplesoft database (Oracle version 11.1.0.6.0) to implement Data Masking.
In our masked environments (a Peoplesoft HR database) we have encountered some applicaton errors due to varchar2
column data sizes being changed from VARCHAR2 (XX CHAR) to VARCHAR2(XX)

This seems to be happening across all masked tables and columns. An example is in PS_NAMES.

The correct definition is this:

desc SYSADM.PS_NAMES
Name                                      Null?    Type
----------------------------------------- -------- ----------------------------
....
FIRST_NAME_SRCH                           NOT NULL VARCHAR2(30 CHAR)
LAST_NAME                                 NOT NULL VARCHAR2(30 CHAR)
FIRST_NAME                                NOT NULL VARCHAR2(30 CHAR)
MIDDLE_NAME                               NOT NULL VARCHAR2(30 CHAR)